Socket CF RFID User Manual page 47

Packaging or covering materials
The Class 2 laser can more effectively scan through difficult packaging materials such as
Mylar (used for electronic components) or thick plastic or glass such as automobile
windshields.
Ambient Light
The Class 2 laser can more effectively scan in high ambient light conditions such as high
intensity lighting or even daylight (indirect sunlight). Scanning bar codes in direct sunlight
is extremely difficult because sunlight contains enough energy in the red spectrum used by
the laser to 'blind' the scanner's decode system.
The second difference between the Class 1 and Class 2 lasers in the CF RFID Reader-Scan
Card is the wavelength frequency of the laser beam. The Class 1 laser has a 670 nanometer
(nm) beam common in most laser bar code scanners, while the Class 2 features a 650 nm
beam. There is no difference in the scanning capability of the two frequencies, but the 650
nm beam is more visible to the human eye, making it appear brighter than the Class 1 laser.
The user must see the oscillating laser beam in order to aim it effectively at the bar code to
be scanned. The Class 2, 650 nm laser is easier to see and aim than the Class 1 laser,
especially when scanning at greater distances, through difficult materials or in high ambient
light.
A third difference between the Class 1 and Class 2 lasers is the current demand during
scanning. At 3.3 Volt power (standard for CompactFlash card slots) the Class 1 laser draws
about 67 milliamps (mA) and the Class 2 laser draws about 75 mA. Both lasers draw about 3
– 4 mA when idle. Therefore, for a given level of scanning activity, using the Class 1 laser
should result in a slightly longer battery life.
A final consideration in the selection of either a Class 1 or Class 2 laser is safety. Staring
directly into any laser beam for an extended period of time will cause damage to the eyes
of humans and animals. The normal use of a bar code scanner is inherently very safe
because (a) the laser is typically aimed away from the person using the scanner, and (b) the
beam oscillates 39 times per second over a 53° arc, making it impossible to stare into the
beam. Additionally, using the lower powered Class 1 laser makes it even less likely that eye
damage will occur. There are certain organizations in Europe, in fact, that require a Class 1
laser in bar code scanners to meet more stringent safety standards. The Socket Mobile CF
RFID Reader-Scan Scan Card with Class 1 laser meets these European safety standards.
Please refer to the Regulatory Compliance section at the end of this User's Guide for more
detailed safety information.
Conclusion
The Class 1 laser is suitable for most applications with expected scanning distances of less
than 20 inches and normal ambient light conditions. The Class 1 laser may be required by
certain European organizations to meet more stringent safety standards. When an
APPENDIX D: CLASS 1 VS. CLASS 2 LASER SCANNERS | 47